Method of producing and operating grinding-wheels



H. BS'NIQHOLS. METHOD 0F PRODUCING AND OPERATING GRINDING WHEELS. APPLIOAZTION FILED JULY 20, 1910. 984,961 a Patented Feb. 21, 1911.

2 SHEETS-SHEET 1.

H. B. NICHOLS. METHOD 0F PRODUGING AND PBRATING GRINDING WHEELS.

APPLIOATION FILED JULY zo, 1910.

984,961 Patented Feb.21,1911.

2 SHEETS-SHEET 2.

UNITED sTATEs PATENT oEEioE.

HENRY B. NICHOLS, or ZPILADELPHIA, PENNSYLVANIA.

METHOD 0F PRODUCING AND OPERATING GRINDING-WHEELS.

To all whom 'it may concern:

.Beit knownthat I, HENRY B. NICHOLS, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful lImprovements in Methods of Producing and Operating Grinding-Wheels, of which 'the following is specification, reference being had therein to the accompanying drawing.

My invention relates to theart of grinding and cutting by means of abrasives, and has for its objectthe production of a grinding body in which a relatively large per cent. of the abrasive material may be usefully employed, with a relatively small per cent. of waste.

An additional object is the provision of means and the method of operation for maintaining the surface speed of the grinding body approximately constant. In grinding wheels especially, the constant 'wear' at the cutting edge, by constant reduction in the diameter produces a corresponding variation in peripheral speed.

The principle involved in my invention is that of constantly feeding or advancing the material ofthe body toward the cutting line to compensatefor Wear, and in the embodi- `ment which I shall herein describe, I make a grinding Wheel of separate sections, which when' the Wheel is new are in immediate contact with each other, and are interlocked along radial lines, being held by clamping plates which can be opened for purposes of adjustment. After. wear the separate blocks or sections of the Wheel'are adjusted by moving them out from the center, and the resulting radial interstices are filled with special interlocking bricks made for the purpqse. After the several sections have become so Worn as to be useless, the filling bricks, having parallel edges, although Worn can still be employed for other wheels.

, I shall not claim herein the apparatus described because -this .forms the subject matter of my prior'application, Serial No. 541,851,

Y filed February 3, 1910.

My invention is illustrated in theiaccom? panying drawings in. which- Figu Fig. 2 is a uadrant thereof with parts broken away, ig. 3 shows a portion of' a wheel after one adjustment, Fig. 4 shows a Specication of Letters Patent. Application 'sued Jury 2o, 1910. serial Nb. 572,910.

re l is a side view of'a new wheel,

Patented Feb. 21, 1911.

similar portion after two adjustments, and Fig. 5 is a diametral section of Fig. 1.

My present invention may be practiced by means .of the apparatus claimed in my prior application aforesaid; and in describing it, I shall find it convenient to do so in terms of the said apparatus.

Referring first to Figs. 1 and 4, the wheel, as a whole, is designated by W, its spindle as S, the,fi-xed'clamping plate as P, and't-hc movable clamping plate as P. The plate P is carried on a flange-j sleeve p, which is.

keyed on a reduced orfshouldered portion a ,of the spindle S. The movable plate P' is fitted to slide freely on thc shaft or spindle, and is held in place by a clamping nut N, having a left hand thread, in order to avoid any danger of its being unscrewed during rotation of the wheel. The plate P has set into its inner face along radial ribs 77 extendlng from the sleeve ring to its periphery, a set of projections p', for a purpose presently to be described; .and both plates P and I are concaved on their inner faces, or provided with peripheral flanges p2, for the purpose of insuring a tight grip on the wheel sections.

Referring now in particular to Fig. 1, it will beobserved that the wheel sections w, w', wz, w3, etc., have their adjacent edges interlocked on sinuous lines' of radial directionas indicated at wt. This mutual engagement of the sections is only possible .when the wheel is new, as each'block or segment is then clamped into its innermost position contiguous to the sleeve p. Besides the 'teeth on its opposite edges, which are intended to resist the action of centrifugal force, each block or segment is provided with a radial channel ws and enlargements 'wc at intervals along its length. The channel L05 1s to serveas a guidein ad]ust1r.g, and rey ceives rib p0 of plate P, and the enlargements or transverse chambers w are to receivef` the thus aior additional security against the action of centrifugal force.

The drawings herewith are taken from a (projections p on the rib, which` 16" wheel, and it will' be noted that there are eight sections or blocks originally making up the wheel, all locked together by thelr toothed edges and clamped between the plates' P, P. The wheel thus'complete is usedA in the ordinary manner, the surface the position shown in Fig. 3, It will be observed that the transverse enlargements v w in the radial grooves, also the .projections Aso on ldenters.` 'Each enlargement, therefore,en gages the next projections in order toward the circumference of the plate, the outermost recess in the brick lying outside the periphery of the plate as indicated at ws".

In moving the bricks out from the center along the line of the radial grooves, they obviously separate, and in the case of a 16 wheel with eight bricks, this first separation amounts to 1%,l or to 1,557 over-.the

ends of the teeth. The interstitial space d'ue to this separation I {ill by inserting-'a' special, long, narrow brick marked B, having its edges serrated to match the serratins in the main wheel segments, but parallel'intheir general direction. Having set'the segments and inserted the bricks B, the plate P', is again set up against the wheel by .tightening the nut N, after which the edge must usually be trued up somewhat; ,but this isa triiing operation, involving the removal of material to a maximum deptlrofonl'y about gsi, which is done very quickly. The wheel is then ready for further use. After being thus reset,when the wheel a second time becomes worn to the permissible limit, that is to say about from the peripheries of the clamping plates, .the bricks are again reset, as shown inlifig.v 4. The operation is the same as before, but it will be observed thateach brick or segment is now so -worn Y that only two of the transverse recesses w" remain, one of which lies Within'the periph.- eries of the clamping plates, and the other without. In this second resetting, the seg'- ments become separated by an interval of of special brick shown in Fig. It and marked Bf.. Thisbrick is similar to the brick B'in that it has parallel serrated edges, and is inserted in the same manner. The plates P P being again clampedtogether onthewheel,

andthe circumference brought to a true curvature, further use is possible, until the resulting wear has caused the grinding edge to again approachto'within the limiting distance of i of the outer edges of the plates. The segments w w may now be vregarded as worn out butit observed that there is very little leftof eachlsegment to be'thrown on the scrap'pile.. Infact, each piece of waste'material will be found the fixed plate P, are 'set 111-" between' 4are all subsidiary features,

l toward by another size' only 1% long, yand wedge-shaped. This saving becomes much more pronounced in larger -wheels as will be immediately apparent upon figuring dimensions. Afterthe wedge-shaped segments fw w j are entirely worn out-the bricks B and'B are still of use, and 'can be employed with new segments orin another wheel. Besides being slightlyconcaved, or' ianged at p2, 'so'as to grasp the'bricks firmly near their outer edges, the'plates P and P are provided with a cushion of some yielding substance, such as blotting paper. In the present case, I prefer to use a very thin rubber packing. i

In a dition to the great economy effected by my invention a very .important advantage gained is that of beingvable torun the wheel at practically a constant speed. The maximum diameter (for the si'ze taken as an illustration) being 164', the minimum diameter is never less than 13%, hence 'very little variation in the surface speed is produced by the wear permitted between adjustments. v

It will beapparent -to those skilled in the,

i art 'that nuferous. changes iii matters of detail can be made without departing from' the principle of my invention, and without sac' rifice of the essential features'thereof. Thus, thematters o f the radial channel w, the serrated edges w, the locking means, etc. and so long as theirfunctions are performed by equivalent elements they'may be changed without altering the invention oreiecting the identity' of -the process.

Having thus described my invention, what I claim and desire to secure by -Letters Patent of the United States, is: d

l. The method of compensating for wear in a grinding wheel which consists in l) dividing the wheel body into sections; 2) each section away-from the center the periphery as the latter is reduced; (3) inserting fillers of abrasive ma'- moving terial between the then vseparated sections;

(4) clamping the sections and fillers together as a unitary inass; and (5) cutting the new peripheral surface of the body to a true circular curvature on the desired radius produced by the previous steps.

2. The method of producing 'a constant grinding surface and compensating for wear on a'grinding body, which'consists in (1) dividing lthe body into sections; (2) advanc.

ing said -sections toward the cutting line as the surface wears; and (3) inserting fillers of similar material between-the sections to maintain the continuity of the .cutting surface.

3. 'Ehe method of producing a constant grinding surface and compensating for wear on a grinding body .having a curved surface, which consists in (1) dividing the body into sections; (2) advancing` said sections step l In teetimony whereof I aix my signature by step toward the line of cut as the surface in presence of two witnesses.

wears; (3) insertin between the sections at euch step fillers of ufcient size to produce HENRY B NICHOLS' 5 continuity of mass; and (4) clamping the Witnesses:

sections together after each step, to main- GEO. B. TAYLOR,

tain said continuity of mass while grinding. CHAS. V. SoUDEBs. 

